Mu'jam Kabir Tabarani 8009 — I was in Damascus on the roof of a house

Abu Ghalib narrates: I was in Damascus on the roof of a house when Sayyiduna Abu Umamah (may Allah be pleased with him) passed by me, so I followed him. We came to the heads of the Khawarij that had been set up on the steps of the mosque, and he said: "The worst of the slain beneath the shade of the sky, and the best of the slain are those whom they killed." I said: Did you hear this from the Messenger of Allah (peace and blessings be upon him)? He said: "Yes, by the Lord of the Ka'bah; yes, by the Lord of the Ka'bah" — several times — then he began to weep. I said: Are you weeping, when you have said what you said? He said: I feel pity for them; they are people who wanted something but did not attain it. Listen, you are in a land where they are many, so may Allah protect you from them.